Exhausting The Aurora

more to follow

Considerations

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Included Stock Equipment

Exhaust Fan

The Aurora ships with an HF-75S Axial Inline Fan:

Specifications

• Product: Inline duct fan
• Model: HF-75S
• Blade material: ABS Plastic
• Diameter: 3''/75 mm
• Voltage: AC 110-120V
• Frequency: 60 Hz
• Current: 0.50/0.42A
• Power: 29/25W
• Speed: 2750/2550 RPM
• Air volume: 46/43 m³/h
• Noise: 26/21 dB
• Protection class: IP44
• Air pressure: 129/114 Pa
• Double speed: Low/High
• Operating temperature: -20 - 60 ℃

Flex Ducting

The Aurora ships with 2 sections of 3" plasticized cloth-reinforced ducting, each measuring xxM (xx') in length (fully extended) for a total of xxM (xx').

Clamps

The Aurora ships with 3 appropriately sized stainless steel hose clamps

Using A Fume Extractor

coming soon

Considerations

more to come

Aurora Exhaust Flow & And Extractor Flow Metering

Teardown & Observations

We discovered that the airflow alarm was being indicated on the BOFA AD Access when connected to t he Aurora. This is not a fault with the laser or the extractor, but rather a calibration thing between the BOFA on-board sensor reference point and the maximum possible inlet flow from the slotted intake port on the Aurora. The extractor and the Aurora both function perfectly, but we wanted to explore this as far as we could just to make sure everything was up to par.

Exhaust modification and results

We removed the rear exhaust port, OEM ducting, and any additional lengths and restrictions by running a continuous duct directly from the extractor to the slotted inlet port on the Aurora to eliminate every variable possible and the flow indicator still persisted. This tells me that the OEM exhaust system is well designed and more than adequate for this application and no modification is needed.

The max inlet flow is a bit lower than the setpoint of the flow indicator in the extractor. This is not a problem, but rather a calibration issue. So we just want to either adjust the inlet flow or , preferably, to simply adjust the extractor reference point to match the aurora max flow rate. Again, this is not affecting the operation or performance of the equipment. We just like to jump down these rabbit holes so we can make sure we dont miss anything.

Quick & Easy Solution

Temporary (or maybe permanent) mass airflow sensor correction of the intake grate limitation (there is probably a calibration for this but i found a perfectly good 'calibrator' in 5 minutes. 

We will see what the BOFA guys say, they probably have a better approach, like maybe just tweaking a trim pot or a setting to match the flow alarm to the laser. 

UPDATE: BOFA support said this is the way to handle it, so we are good to go.